Page 19 - Ebook Trigonometri_Krisna Hasugian_MESP 2019

Find a missing side length given an angle measure

Suppose you are given an angle measure and a side length, can you find the
remaining side lengths?

Yes. You can use the trig functions to formulate an equation to find missing side
lengths of a right triangle.

Example 16

First we know that sin = , therefore sin 30 =
ℎ 5
Next we solve for x, 5 ⋅ sin 30 =

Use your TI calculator to compute 5 ⋅ sin 30,

And you find out = 2.5

Let’s see another example,

Example 17 We are given information about the opposite and adjacent
sides of the triangle, so we will use tan
16
tan 52 =

16
=
tan 52
≈ 12.5

Need more help? Click below for a Learning Video 2

Khan Academy video 3

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